Exhausts Rust

Rusty exhaust MIG method

Rusty exhaust (corrosion blow holes) MIG method, on/off/on building up thinned  edges

'Nicola&Tony: I'm a novice welder but I want to have a go at welding some small holes in the silencer box for our lt. I'll post some pics of the holes when the rain stops. I've got the exhaust off the van at the moment.

Just wondering if anybody has tips / advice about doing this sort of thing. I guess the main problem will be blowing holes in thin steel (I have 0.6mm wire in my mig so hopefully that will help) and the fact that I'll probably not be able to clean it back to shiny steel (I've never tried welding rusty stuff before).

I'll be using CO2 for the shielding gas but would make a temporary switch to an argonCO2 disposable if it'll make this job easier / more successful.

Any info would be much appreciated. Cheerss Tony

CovKid: You could cut a disc of metal and weld it on to complete end possibly - be more to weld to then.

Weldore: Turn the welder down low and try and do a line of weld either side of the hole and bridge the gap Just co2 will be fine for that. Don't try and do a run... do lots of on and off's and leave a second or so between welds. If it doesnt want it then make a patch for it, welding to better metal

'Rozzo: Just clean it back to good metal tone (even if that means making the hole 3 inch long by 1 inch wide!) Then tap the area as flat as you can get it (that ridge will knock flat) and then cut a slightly oversized patch, start on/offing at one end and tap it down onto the box as you go whilst it's glowing red. Simple

HarryMann: Hit it hard with a wire brush (stainless brush is best) to find widest extent of perforation Straight C02, 1 Max or 2 min, feed 5.5 to 6 (approx on a Clarke 151TE), thicken edges with on/off/on/off, then join them up, if you can't move in and fill bigger holes, then thin cover plate, keep brushing all the time to remove any contamination...

Just develop the technique of thickening the dodgy edges, if they burn back further, then brush again, move back with them, thickening and working all around perimeter of the rust hole...

Prior to welding